| Call | # times | What's it doing? |
|---|---|---|
| fib($n, 5) | 1 | Collecting all promises; waiting for and summing the result |
| fib($, 4) | 2 | Returning promises |
| fib($, 3) | 4 | Returning promises |
| fib($, 2) | 8 | Returning promises |
| fib($, 1) | 16 | Creating promises |
| fib($, 0) | 32+ | Figuring out the answer |